WNBA star Brittney Griner is sharing her story for the first time after being confined to a Russian prison, in a special edition of 20/20.

In a clip of the emotional interview, Griner shared her experience of being isolated in a foreign country.

“I was just so scared for everything because there's so much unknown,” Griner told Robin Roberts, co-anchor of Good Morning America.

On Feb. 17, 2022,  Griner was detained at Sheremetyevo International Airport in Khimki after being accused of having vape cartridges containing hashish oil, which is illegal in the country. Griner was heading back to Russia after the completion of WNBA's off-season with the Phoenix Suns.

Roberts asked what was going on in her mind when she realized that the cartridges were in her luggage. Griner shared that she immediately knew that the consequences could be devastating.

“My life is over right here,” Griner answered.

Griner plead guilty to drug charges on July 7, 2022, saying that she accidentally packed the vape cartridges in her luggage. During court, she testified that she did not intentionally break Russian law.

Eventually, Griner was sentenced to nine years in prison. Her attorneys filed an appeal on her behalf but a judge rejected it on Oct. 25, 2022.

After she was sentenced, Griner was transferred to a penal colony in the Russian region of Mordovia to serve her time.

“The mattress had a huge blood stain on it. I had no soap, no toilet paper. That was the moment where I just felt less than a human,” she recalled.

Griner said that the conditions she faced were so terrible that she had thoughts of ending her life.

“I just didn't think I could get through what I needed to get through,” she said.

After almost 10 months of being imprisoned, Griner was released on Dec. 8, 2022, in a prisoner exchange. According to the terms of the deal, Griner was swapped for Viktor Bout, a convicted Russian arms dealer.

Since her release, Griner has become an advocate for Paul Whelan and Evan Gershkovich, Americans who are imprisoned in Russia.

In addition to the exclusive interview, Griner's story will be the subject of an ESPN documentary and a potential scripted series with ABC detailing her experience.

“The last two years have been the most harrowing, transformative, and illuminating period of my life, and I am grateful to be in a place now to share my story with the world,” Griner said in a statement at the time. “I’m proud to partner with ESPN and Disney to share this very personal story because of its incredible potential to inspire hope around the world and their proven ability to do just that.”

The full interview is set to air May 1 on 20/20 on ABC.